A problem in the electronics industry is that of access to power. Almost all modern devices require power that originates from a wall outlet. Therefore, wireless electricity has been sought after as an attractive solution that would allow users to access energy without the use of electrical cords and outlets. Moreover, the promise of spatial freedom, mobility, and motion also urge the use of wireless power. Unfortunately, current commercial wireless chargers come in the form of wireless mats, which require the target device to be placed on top, or within a few centimeters, of the mat. These induction-based solutions are scientifically inefficient at transmitting power at long distances on the order of meters. Therefore far-field solutions must be implemented for long-range wireless power.
Far-field transmission's primary problem—which is the source of one of its advantages—is the directionality of the electromagnetic (EM) waves. Because these waves experience beamforming, the EM waves act as spotlights, only transmitting in one direction. The antenna's gain would be correlated with the beamwidth is (i.e. narrow vs broad vs isotropic). This directionality poses the problem of mobility and motion; because the waves only face one direction, a user who steps out of the field or is positioned elsewhere in the space will not receive power.